BLTBYBank

📋 Contract Overview

Property	Value
📁 File	src/BLTBYBank.sol
🔧 Type	Upgradeable UUPS Proxy
⚙️ Solidity	0.8.33
📜 License	MIT

🎯 Purpose: Primary on-chain marketplace for BLTBY tokens—managing token sales, purchases, and liquidity at fair market prices.

---

🏪 Core Functions

🏪 Core Functions

Function	Description
💰 Token Purchases	Buy BLTBY with stablecoins
💸 Token Sales	Sell BLTBY for stablecoins
📊 Price Discovery	Fair market pricing
🏦 Liquidity Management	Maintain buy/sell liquidity

⚙️ Specifications

🔐 Roles

---

🔧 Functions

💰 Buy

💰 Token Purchases

Buy with Stablecoin Amount

function buyBLTBY(
    address stablecoin,
    uint256 stablecoinAmount
) external nonReentrant returns (uint256 bltbyAmount)

Access: Any address

Flow:

1. Verify stablecoin is accepted

2. Check daily limits

3. Calculate BLTBY amount based on buy price

4. Transfer stablecoin from buyer

5. Transfer BLTBY to buyer

6. Update reserves and tracking

Buy Exact BLTBY Amount

function buyBLTBYExact(
    address stablecoin,
    uint256 bltbyAmount
) external nonReentrant returns (uint256 stablecoinCost)

Buy exact amount of BLTBY (calculates stablecoin needed).

💸 Sell

📊 Pricing

🏦 Liquidity

👁️ View

---

📊 Pricing Model

The buy/sell spread provides revenue and protects against arbitrage.

Spread Calculation

function _calculatePrices() internal view returns (uint256 buy, uint256 sell) {
    uint256 midPrice = _getMidPrice();
    uint256 halfSpread = (midPrice * spread) / 20000;  // spread/2

    buy = midPrice + halfSpread;
    sell = midPrice - halfSpread;
}

Example Pricing

Mid Price	Spread	Buy Price	Sell Price
$0.10	2%	$0.101	$0.099
$0.10	5%	$0.1025	$0.0975

---

📅 Daily Limits

Limits protect the bank from rapid drainage.

Limit Type	Purpose
📊 Per transaction	Max single trade size
📅 Daily buy limit	Max user can buy per day
📅 Daily sell limit	Max user can sell per day

Limits reset at midnight UTC.

---

📜 Events & Errors

📢 Events

event BLTBYPurchased(
    address indexed buyer,
    address indexed stablecoin,
    uint256 stablecoinAmount,
    uint256 bltbyAmount,
    uint256 price
);
event BLTBYSold(
    address indexed seller,
    address indexed stablecoin,
    uint256 bltbyAmount,
    uint256 stablecoinAmount,
    uint256 price
);
event PricesUpdated(uint256 newBuyPrice, uint256 newSellPrice);
event LiquidityAdded(address indexed token, uint256 amount);
event LiquidityWithdrawn(address indexed token, uint256 amount, address indexed destination);

⛔ Errors

---

💰 Treasury Integration

A portion of each transaction goes to treasury.

Transaction	Fee
💰 Buy	0.5% of stablecoin spent
💸 Sell	0.5% of stablecoin received

---

🏦 Liquidity Health

function getLiquidityHealth() external view returns (
    uint256 bltbyRatio,
    uint256 stablecoinRatio,
    bool isHealthy
)

Returns:

• Ratio of current reserves to target

• Overall health status

If reserves fall too low, additional liquidity should be added.

---

🔗 Contract Interactions

Contract	Interaction
🪙 BLTBYToken	Transfers for buys/sells
🏦 Treasury	Receives fees
📊 Price Oracle	Price discovery (optional)
💵 Stablecoins	Payment tokens

---

🔒 Security Features

Protection	How It Works
📅 Daily limits	Prevent large dumps/pumps
📊 Spread	Buffer against arbitrage
📈 Price bounds	Prevent extreme moves
🔐 Role-based access	Only authorized price changes

---

💻 Integration Examples

Buying BLTBY

// Get quote
const quote = await bltbyBank.getBuyQuote(parseUnits("100", 6)); // $100
console.log(`Will receive ${formatEther(quote)} BLTBY`);

// Approve USDC
await usdc.approve(bltbyBank.address, parseUnits("100", 6));

// Execute buy
await bltbyBank.buyBLTBY(usdcAddress, parseUnits("100", 6));

Selling BLTBY

// Get quote
const quote = await bltbyBank.getSellQuote(parseEther("1000")); // 1000 BLTBY
console.log(`Will receive $${formatUnits(quote, 6)}`);

// Approve BLTBY
await bltbyToken.approve(bltbyBank.address, parseEther("1000"));

// Execute sell
await bltbyBank.sellBLTBY(usdcAddress, parseEther("1000"));

Checking Limits

const { remainingBuyToday, remainingSellToday } = await bltbyBank.getUserLimits(userAddress);

---

🔗 Related Pages

BLTBYTokenTreasuryBLTBY Token